1 Background

Ground level ozone formation mostly occurs when nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOCs), react in the atmosphere in the presence of UV (sunlight). Motor vehicle exhaust, industrial emissions, and chemical solvents are the major sources of these pollutants in urban areas, although winds can carry NOx hundreds of kilometers, causing ozone formation to occur in less populated regions as well. Ground level ozone can be harmful to human health in higher concentrations with the NIOSH recommended exposure limit for ozone to be 0.1 ppm (0.2 mg/m3).

2 California Ozone Data

Taking a look at the California ozone data in 2005 from the California Air Resources Board (CARB), we see that the data are composed of date, location, concentration, and spatial geometry columns. This spatial geometry data allows us to use GIS mapping packages, such as leaflet used here, to plot our data across a spatial area.

California Ozone Concentration Data
Index Date Site O3 geometry
1 20050808 2008 0.044 POINT (-120.0258 34.4622)
2 20050808 2013 0.081 POINT (-119.7413 36.7055)
3 20050808 2016 0.035 POINT (-121.7333 36.4819)
4 20050808 2032 0.080 POINT (-119.2908 36.3325)
5 20050808 2040 0.053 POINT (-117.1289 32.8364)
6 20050808 2077 0.077 POINT (-117.1477 34.0588)
7 20050808 2088 0.051 POINT (-119.3152 34.2805)
8 20050808 2094 0.059 POINT (-121.2688 37.9516)
9 20050808 2102 0.041 POINT (-121.8836 38.0169)
10 20050808 2105 0.027 POINT (-122.7091 38.4436)
11 20050808 2114 0.090 POINT (-119.5036 36.5975)
12 20050808 2115 0.069 POINT (-121.8422 39.7575)
13 20050808 2123 0.057 POINT (-121.3811 38.7122)
14 20050808 2125 0.029 POINT (-122.2033 37.4824)
15 20050808 2143 0.052 POINT (-121.773 38.5352)
16 20050808 2160 0.083 POINT (-118.1277 34.1322)
17 20050808 2199 0.068 POINT (-116.4899 33.8194)
18 20050808 2208 0.078 POINT (-120.1847 39.3274)
19 20050808 2221 0.096 POINT (-117.2736 34.1066)
20 20050808 2225 0.019 POINT (-122.2672 37.8013)
21 20050808 2249 0.065 POINT (-117.9522 33.9252)
22 20050808 2263 0.061 POINT (-117.0753 33.1278)
23 20050808 2266 0.094 POINT (-117.4922 34.1005)
24 20050808 2293 0.035 POINT (-121.9616 37.5358)
25 20050808 2312 0.097 POINT (-118.8505 35.3458)
26 20050808 2320 0.057 POINT (-121.5752 36.9997)
27 20050808 2321 0.036 POINT (-120.8428 35.3664)
28 20050808 2327 0.060 POINT (-116.9424 32.7908)
29 20050808 2329 0.032 POINT (-122.1939 37.0119)
30 20050808 2360 0.036 POINT (-120.4577 34.6377)
31 20050808 2368 0.051 POINT (-117.2633 32.9524)
32 20050808 2373 0.029 POINT (-122.3977 37.7661)
33 20050808 2410 0.030 POINT (-122.238 38.1025)
34 20050808 2420 0.105 POINT (-118.5327 34.1991)
35 20050808 2429 0.047 POINT (-118.1894 33.8241)
36 20050808 2460 0.078 POINT (-116.7683 32.8422)
37 20050808 2484 0.084 POINT (-117.9239 34.1364)
38 20050808 2485 0.095 POINT (-117.6288 34.1033)
39 20050808 2492 0.079 POINT (-118.3169 34.1758)
40 20050808 2494 0.067 POINT (-118.4566 34.0505)
41 20050808 2499 0.094 POINT (-117.2755 34.2413)
42 20050808 2525 0.081 POINT (-117.2277 33.7888)
43 20050808 2551 0.077 POINT (-115.5631 32.7922)
44 20050808 2583 0.048 POINT (-118.2108 33.9288)
45 20050808 2589 0.052 POINT (-117.0592 32.6314)
46 20050808 2593 0.059 POINT (-120.0733 34.6077)
47 20050808 2596 0.101 POINT (-117.4152 34.0005)
48 20050808 2613 0.038 POINT (-121.9791 37.228)
49 20050808 2622 0.028 POINT (-122.5183 37.9727)
50 20050808 2628 0.046 POINT (-121.3622 36.8433)
51 20050808 2650 0.089 POINT (-117.2861 34.4158)
52 20050808 2655 0.033 POINT (-122.2941 38.3113)
53 20050808 2671 0.036 POINT (-120.6322 35.1239)
54 20050808 2709 0.034 POINT (-120.6578 35.2822)
55 20050808 2731 0.078 POINT (-121.3678 38.6136)
56 20050808 2744 0.062 POINT (-121.998 39.1888)
57 20050808 2752 0.056 POINT (-122.6336 41.7267)
58 20050808 2772 0.085 POINT (-119.0167 35.4381)
59 20050808 2804 0.041 POINT (-121.6413 38.0066)
60 20050808 2806 0.029 POINT (-122.0305 37.6541)
61 20050808 2829 0.059 POINT (-122.3808 40.5514)
62 20050808 2830 0.115 POINT (-117.5897 34.425)
63 20050808 2831 0.043 POINT (-122.0247 37.9391)
64 20050808 2833 0.082 POINT (-120.9942 37.6419)
65 20050808 2844 0.094 POINT (-119.8828 36.8417)
66 20050808 2849 0.099 POINT (-117.8499 34.1444)
67 20050808 2878 0.059 POINT (-116.2158 33.7083)
68 20050808 2880 0.089 POINT (-118.6836 34.2761)
69 20050808 2891 0.093 POINT (-121.1055 38.9394)
70 20050808 2894 0.038 POINT (-121.1152 36.2269)
71 20050808 2898 0.099 POINT (-117.75 34.0666)
72 20050808 2899 0.064 POINT (-118.2267 34.0664)
73 20050808 2914 0.050 POINT (-122.9219 39.033)
74 20050808 2919 0.068 POINT (-119.4027 35.0513)
75 20050808 2923 0.079 POINT (-117.0244 34.8938)
76 20050808 2933 0.041 POINT (-116.9383 32.5516)
77 20050808 2937 0.056 POINT (-117.9258 33.6738)
78 20050808 2941 0.094 POINT (-118.7758 35.2086)
79 20050808 2943 0.082 POINT (-117.3309 33.6763)
80 20050808 2954 0.051 POINT (-120.1963 34.5275)
81 20050808 2955 0.071 POINT (-120.6549 35.6147)
82 20050808 2956 0.077 POINT (-121.2647 38.7461)
83 20050808 2957 0.063 POINT (-119.7911 34.5416)
84 20050808 2958 0.063 POINT (-121.6191 39.1388)
85 20050808 2965 0.061 POINT (-120.6681 35.4917)
86 20050808 2968 0.068 POINT (-120.3786 37.9819)
87 20050808 2969 0.039 POINT (-121.8422 37.3913)
88 20050808 2972 0.061 POINT (-121.5764 40.5372)
89 20050808 2973 0.024 POINT (-122.1163 37.7099)
90 20050808 2977 0.054 POINT (-121.4208 38.3025)
91 20050808 2981 0.082 POINT (-119.2725 35.5036)
92 20050808 2983 0.061 POINT (-121.1717 36.4991)
93 20050808 2984 0.065 POINT (-118.87 34.2099)
94 20050808 2985 0.036 POINT (-121.7872 36.9325)
95 20050808 2991 0.054 POINT (-119.1431 34.2522)
96 20050808 2992 0.046 POINT (-120.4258 34.7233)
97 20050808 2993 0.067 POINT (-120.7644 38.3427)
98 20050808 2996 0.073 POINT (-120.8364 37.4883)
99 20050808 2997 0.050 POINT (-115.5164 32.6739)
100 20050808 3002 0.105 POINT (-120.9541 39.0997)
101 20050808 3003 0.029 POINT (-119.4572 34.4033)
102 20050808 3009 0.102 POINT (-119.7731 36.7819)
103 20050808 3010 0.055 POINT (-123.2002 39.1447)
104 20050808 3011 0.053 POINT (-121.4936 38.568)
105 20050808 3017 0.090 POINT (-120.8219 38.7247)
106 20050808 3018 0.063 POINT (-119.7058 37.7133)
107 20050808 3020 0.055 POINT (-120.9441 39.9397)
108 20050808 3022 0.082 POINT (-120.4336 37.2817)
109 20050808 3023 0.041 POINT (-120.6327 34.5961)
110 20050808 3026 0.097 POINT (-119.7164 36.8194)
111 20050808 3032 0.079 POINT (-122.2986 40.4531)
112 20050808 3036 0.097 POINT (-118.773 36.564)
113 20050808 3101 0.056 POINT (-120.0458 34.4897)
114 20050808 3116 0.036 POINT (-123.3497 39.4044)
115 20050808 3117 0.078 POINT (-121.75 39.1583)
116 20050808 3121 0.061 POINT (-118.1478 35.0503)
117 20050808 3124 0.066 POINT (-116.0553 34.1419)
118 20050808 3126 0.092 POINT (-121.0555 39.2336)
119 20050808 3129 0.070 POINT (-119.6436 36.3147)
120 20050808 3133 0.039 POINT (-122.0144 37.0522)
121 20050808 3135 0.096 POINT (-115.4831 32.6761)
122 20050808 3137 0.065 POINT (-122.1897 39.5172)
123 20050808 3138 0.043 POINT (-116.9869 32.5308)
124 20050808 3140 0.067 POINT (-121.5999 37.0794)
125 20050808 3141 0.049 POINT (-116.9763 32.4975)
126 20050808 3143 0.086 POINT (-115.6236 33.0325)
127 20050808 3144 0.079 POINT (-120.6802 38.2019)
128 20050808 3145 0.073 POINT (-119.0144 35.3853)
129 20050808 3146 0.081 POINT (-119.0627 35.3566)
130 20050808 3151 0.080 POINT (-116.8478 36.5089)
131 20050808 3152 0.073 POINT (-116.3888 34.0694)
132 20050808 3153 0.043 POINT (-119.8283 34.4455)
133 20050808 3157 0.083 POINT (-120.8456 39.3181)
134 20050808 3158 0.080 POINT (-122.0928 40.2622)
135 20050808 3161 0.068 POINT (-119.8416 37.5466)
136 20050808 3168 0.077 POINT (-116.8583 33.9208)
137 20050808 3172 0.077 POINT (-119.2458 34.4166)
138 20050808 3178 0.048 POINT (-117.1163 32.5136)
139 20050808 3183 0.046 POINT (-117.0558 32.3533)
140 20050808 3186 0.066 POINT (-115.5453 33.2136)
141 20050808 3187 0.102 POINT (-121.1644 38.683)
142 20050808 3196 0.111 POINT (-121 38.8906)
143 20050808 3197 0.079 POINT (-122.2366 40.1749)
144 20050808 3198 0.047 POINT (-117.3961 33.2169)
145 20050808 3200 0.037 POINT (-121.9908 36.9839)
146 20050808 3209 0.067 POINT (-121.2277 38.4719)
147 20050808 3211 0.071 POINT (-120.01 36.8672)
148 20050808 3215 0.072 POINT (-117.3722 35.7744)
149 20050808 3223 0.100 POINT (-121.5144 38.6366)
150 20050808 3249 0.071 POINT (-121.7305 38.6605)
151 20050808 3251 0.038 POINT (-120.5008 35.0316)
152 20050808 3255 0.074 POINT (-116.6186 32.575)
153 20050808 3265 0.075 POINT (-117.6755 33.6297)
154 20050808 3415 0.035 POINT (-122.0758 38.2269)
155 20050808 3484 0.100 POINT (-118.8341 36.4911)
156 20050808 3486 0.036 POINT (-120.4355 34.943)
157 20050808 3487 0.058 POINT (-120.0331 38.8117)
158 20050808 3489 0.035 POINT (-121.6233 36.6941)
159 20050808 3490 0.049 POINT (-121.78 37.68)
160 20050808 3491 0.079 POINT (-121.6177 39.7141)
161 20050808 3500 0.084 POINT (-117.325 34.5122)
162 20050808 3502 0.112 POINT (-118.5283 34.3833)
163 20050808 3505 0.082 POINT (-118.8097 34.4044)
164 20050808 3507 0.028 POINT (-122.0511 37.3558)
165 20050808 3658 0.111 POINT (-118.1305 34.6713)
166 20050808 3661 0.037 POINT (-121.8947 37.3483)
167 20050808 3664 0.051 POINT (-119.5938 37.743)
168 20050808 3665 0.044 POINT (-119.6908 34.4278)
169 20050808 3668 0.027 POINT (-122.3566 37.9602)
170 20050808 3673 0.053 POINT (-114.6005 33.6121)
171 20050808 3674 0.080 POINT (-117.9384 33.8306)
172 20050808 3678 0.044 POINT (-121.95 38.3583)
173 20050808 3683 0.059 POINT (-118.0433 33.9508)
174 20050808 3685 0.055 POINT (-119.9952 38.9102)
175 20050808 3690 0.054 POINT (-117.1527 32.7013)

3 Ozone Density

Plotting the density shows that the average concentration of ozone is about 0.065, and has multiple peaks, such as at concentrations of 0.036,0.059, and 0.079. This likely helps to establish the average since both high peaks are on either side of the mean.

4 Interactive Spatial Map

Plotting the ozone concentration data in leaflet and overlaying a heatmap shows that the highest concentrations of ozone occur in the Los Angeles, and Sacramento areas.

5 Surface map

To get a different look on the spatial ozone concentration, a kernel density plot was created. This shows the two high concentration areas as the previous plot (Los Angeles, and Sacramento), but also gives a better picture of the areas around the two cities. Looking a the two peaks, we can see that one peak (Sacramento) tapers off quickly as we move away, while the other peak (Los Angeles) tapers off more gradually.

6 Historic Ozone Concentration Data

To see how the ozone concentration has changed over time, historic data from the California Air Resources Board (CARB) was used along with global temperature anomaly data from NASA. Looking at the data table below, we see that the data consists of date, location, annual average ozone concentration, latitude, longitude, ground elevation, and the temperature change columns.

California Ozone Concentration and Global Temperature Anomaly Data
Date LOCATION ANNUAL LATITUDE LONGITUDE ELEVATION Lowess
1 1980 2008 0.120 34.46222 -120.0258 24 0.20
2 1980 2460 0.230 32.84220 -116.7683 603 0.20
3 1980 2899 0.290 34.06640 -118.2267 87 0.20
4 1980 2898 0.370 34.06667 -117.7500 270 0.20
5 1980 2655 0.120 38.31139 -122.2942 22 0.20
6 1980 2525 0.290 33.78889 -117.2278 439 0.20
7 1980 2249 0.310 33.92528 -117.9522 82 0.20
8 1980 2589 0.160 32.63140 -117.0592 56 0.20
9 1980 2991 0.130 34.25220 -119.1431 34 0.20
10 1980 2499 0.320 34.24139 -117.2756 1384 0.20
11 1980 2420 0.380 34.19917 -118.5328 226 0.20
12 1980 2040 0.180 32.83640 -117.1289 135 0.20
13 1980 2484 0.410 34.13640 -117.9239 183 0.20
14 1980 2596 0.370 34.00056 -117.4153 250 0.20
15 1980 2492 0.350 34.17580 -118.3169 168 0.20
16 1980 2199 0.210 33.81944 -116.4900 171 0.20
17 1980 2125 0.150 37.48250 -122.2033 9 0.20
18 1980 2293 0.190 37.53583 -121.9617 24 0.20
19 1980 2102 0.130 38.01694 -121.8836 9 0.20
20 1980 2410 0.140 38.10250 -122.2381 30 0.20
21 1981 2410 0.120 38.10250 -122.2381 30 0.21
22 1981 2199 0.190 33.81944 -116.4900 171 0.21
23 1981 2525 0.240 33.78889 -117.2278 439 0.21
24 1981 2484 0.350 34.13640 -117.9239 183 0.21
25 1981 2293 0.160 37.53583 -121.9617 24 0.21
26 1981 2125 0.130 37.48250 -122.2033 9 0.21
27 1981 2420 0.250 34.19917 -118.5328 226 0.21
28 1981 2460 0.190 32.84220 -116.7683 603 0.21
29 1981 2249 0.270 33.92528 -117.9522 82 0.21
30 1981 2102 0.110 38.01694 -121.8836 9 0.21
31 1981 2008 0.110 34.46222 -120.0258 24 0.21
32 1981 2655 0.110 38.31139 -122.2942 22 0.21
33 1981 2499 0.350 34.24139 -117.2756 1384 0.21
34 1981 2040 0.200 32.83640 -117.1289 135 0.21
35 1981 2596 0.300 34.00056 -117.4153 250 0.21
36 1981 2589 0.170 32.63140 -117.0592 56 0.21
37 1981 2898 0.330 34.06667 -117.7500 270 0.21
38 1981 2492 0.270 34.17580 -118.3169 168 0.21
39 1981 2991 0.160 34.25220 -119.1431 34 0.21
40 1981 2899 0.320 34.06640 -118.2267 87 0.21
41 1982 2199 0.190 33.81944 -116.4900 171 0.22
42 1982 2040 0.230 32.83640 -117.1289 135 0.22
43 1982 2102 0.100 38.01694 -121.8836 9 0.22
44 1982 2410 0.100 38.10250 -122.2381 30 0.22
45 1982 2008 0.150 34.46222 -120.0258 24 0.22
46 1982 2249 0.320 33.92528 -117.9522 82 0.22
47 1982 2484 0.360 34.13640 -117.9239 183 0.22
48 1982 2125 0.100 37.48250 -122.2033 9 0.22
49 1982 2492 0.250 34.17580 -118.3169 168 0.22
50 1982 2589 0.200 32.63140 -117.0592 56 0.22
51 1982 2525 0.280 33.78889 -117.2278 439 0.22
52 1982 2293 0.140 37.53583 -121.9617 24 0.22
53 1982 2499 0.320 34.24139 -117.2756 1384 0.22
54 1982 2596 0.310 34.00056 -117.4153 250 0.22
55 1982 2420 0.220 34.19917 -118.5328 226 0.22
56 1982 2460 0.180 32.84220 -116.7683 603 0.22
57 1982 2991 0.150 34.25220 -119.1431 34 0.22
59 1982 2899 0.400 34.06640 -118.2267 87 0.22
60 1982 2898 0.310 34.06667 -117.7500 270 0.22
61 1983 2008 0.140 34.46222 -120.0258 24 0.21
62 1983 2102 0.140 38.01694 -121.8836 9 0.21
63 1983 2125 0.170 37.48250 -122.2033 9 0.21
64 1983 2293 0.160 37.53583 -121.9617 24 0.21
65 1983 2040 0.280 32.83640 -117.1289 135 0.21
66 1983 2484 0.390 34.13640 -117.9239 183 0.21
67 1983 2460 0.180 32.84220 -116.7683 603 0.21
68 1983 2249 0.270 33.92528 -117.9522 82 0.21
69 1983 2199 0.190 33.81944 -116.4900 171 0.21
70 1983 2525 0.260 33.78889 -117.2278 439 0.21
71 1983 2655 0.110 38.31139 -122.2942 22 0.21
72 1983 2492 0.310 34.17580 -118.3169 168 0.21
73 1983 2410 0.130 38.10250 -122.2381 30 0.21
74 1983 2420 0.260 34.19917 -118.5328 226 0.21
75 1983 2898 0.340 34.06667 -117.7500 270 0.21
76 1983 2499 0.280 34.24139 -117.2756 1384 0.21
77 1983 2589 0.210 32.63140 -117.0592 56 0.21
78 1983 2899 0.260 34.06640 -118.2267 87 0.21
79 1983 2991 0.150 34.25220 -119.1431 34 0.21
80 1983 2596 0.360 34.00056 -117.4153 250 0.21
81 1984 2040 0.280 32.83640 -117.1289 135 0.21
82 1984 2199 0.200 33.81944 -116.4900 171 0.21
83 1984 2008 0.140 34.46222 -120.0258 24 0.21
84 1984 2125 0.110 37.48250 -122.2033 9 0.21
85 1984 2102 0.160 38.01694 -121.8836 9 0.21
86 1984 2249 0.320 33.92528 -117.9522 82 0.21
87 1984 2410 0.140 38.10250 -122.2381 30 0.21
88 1984 2484 0.310 34.13640 -117.9239 183 0.21
89 1984 2293 0.150 37.53583 -121.9617 24 0.21
90 1984 2460 0.160 32.84220 -116.7683 603 0.21
91 1984 2492 0.260 34.17580 -118.3169 168 0.21
92 1984 2589 0.150 32.63140 -117.0592 56 0.21
93 1984 2525 0.220 33.78889 -117.2278 439 0.21
94 1984 2655 0.110 38.31139 -122.2942 22 0.21
95 1984 2499 0.340 34.24139 -117.2756 1384 0.21
96 1984 2596 0.320 34.00056 -117.4153 250 0.21
97 1984 2420 0.260 34.19917 -118.5328 226 0.21
98 1984 2898 0.310 34.06667 -117.7500 270 0.21
99 1984 2991 0.140 34.25220 -119.1431 34 0.21
100 1984 2899 0.290 34.06640 -118.2267 87 0.21
101 1985 2008 0.130 34.46222 -120.0258 24 0.22
102 1985 2040 0.220 32.83640 -117.1289 135 0.22
103 1985 2199 0.240 33.81944 -116.4900 171 0.22
104 1985 2410 0.120 38.10250 -122.2381 30 0.22
105 1985 2125 0.130 37.48250 -122.2033 9 0.22
106 1985 2102 0.140 38.01694 -121.8836 9 0.22
107 1985 2293 0.150 37.53583 -121.9617 24 0.22
108 1985 2249 0.340 33.92528 -117.9522 82 0.22
109 1985 2492 0.300 34.17580 -118.3169 168 0.22
110 1985 2484 0.360 34.13640 -117.9239 183 0.22
111 1985 2525 0.290 33.78889 -117.2278 439 0.22
112 1985 2460 0.220 32.84220 -116.7683 603 0.22
113 1985 2655 0.110 38.31139 -122.2942 22 0.22
114 1985 2499 0.300 34.24139 -117.2756 1384 0.22
115 1985 2589 0.200 32.63140 -117.0592 56 0.22
116 1985 2420 0.250 34.19917 -118.5328 226 0.22
117 1985 2898 0.330 34.06667 -117.7500 270 0.22
118 1985 2991 0.150 34.25220 -119.1431 34 0.22
119 1985 2596 0.350 34.00056 -117.4153 250 0.22
120 1985 2899 0.300 34.06640 -118.2267 87 0.22
121 1986 2040 0.150 32.83640 -117.1289 135 0.24
122 1986 2199 0.180 33.81944 -116.4900 171 0.24
123 1986 2008 0.110 34.46222 -120.0258 24 0.24
124 1986 2293 0.140 37.53583 -121.9617 24 0.24
126 1986 2125 0.100 37.48250 -122.2033 9 0.24
127 1986 2102 0.100 38.01694 -121.8836 9 0.24
128 1986 2499 0.260 34.24139 -117.2756 1384 0.24
129 1986 2249 0.250 33.92528 -117.9522 82 0.24
130 1986 2460 0.160 32.84220 -116.7683 603 0.24
131 1986 2484 0.310 34.13640 -117.9239 183 0.24
132 1986 2898 0.270 34.06667 -117.7500 270 0.24
133 1986 2525 0.220 33.78889 -117.2278 439 0.24
134 1986 2420 0.220 34.19917 -118.5328 226 0.24
135 1986 2492 0.280 34.17580 -118.3169 168 0.24
136 1986 2899 0.220 34.06640 -118.2267 87 0.24
137 1986 2589 0.140 32.63140 -117.0592 56 0.24
138 1986 2596 0.250 34.00056 -117.4153 250 0.24
140 1986 2991 0.180 34.25220 -119.1431 34 0.24
141 1987 2410 0.110 38.10250 -122.2381 30 0.27
142 1987 2008 0.170 34.46222 -120.0258 24 0.27
143 1987 2040 0.170 32.83640 -117.1289 135 0.27
144 1987 2484 0.300 34.13640 -117.9239 183 0.27
145 1987 2199 0.170 33.81944 -116.4900 171 0.27
146 1987 2102 0.150 38.01694 -121.8836 9 0.27
147 1987 2460 0.170 32.84220 -116.7683 603 0.27
148 1987 2492 0.230 34.17580 -118.3169 168 0.27
149 1987 2125 0.120 37.48250 -122.2033 9 0.27
150 1987 2249 0.240 33.92528 -117.9522 82 0.27
151 1987 2589 0.160 32.63140 -117.0592 56 0.27
152 1987 2420 0.220 34.19917 -118.5328 226 0.27
153 1987 2293 0.160 37.53583 -121.9617 24 0.27
154 1987 2525 0.200 33.78889 -117.2278 439 0.27
155 1987 2991 0.180 34.25220 -119.1431 34 0.27
156 1987 2596 0.290 34.00056 -117.4153 250 0.27
157 1987 2655 0.110 38.31139 -122.2942 22 0.27
158 1987 2499 0.290 34.24139 -117.2756 1384 0.27
159 1987 2899 0.220 34.06640 -118.2267 87 0.27
160 1987 2898 0.290 34.06667 -117.7500 270 0.27
161 1988 2199 0.200 33.81944 -116.4900 171 0.31
162 1988 2008 0.110 34.46222 -120.0258 24 0.31
163 1988 2410 0.120 38.10250 -122.2381 30 0.31
164 1988 2125 0.100 37.48250 -122.2033 9 0.31
165 1988 2102 0.120 38.01694 -121.8836 9 0.31
166 1988 2040 0.220 32.83640 -117.1289 135 0.31
167 1988 2484 0.300 34.13640 -117.9239 183 0.31
168 1988 2293 0.130 37.53583 -121.9617 24 0.31
169 1988 2249 0.290 33.92528 -117.9522 82 0.31
170 1988 2655 0.100 38.31139 -122.2942 22 0.31
171 1988 2525 0.230 33.78889 -117.2278 439 0.31
172 1988 2460 0.190 32.84220 -116.7683 603 0.31
173 1988 2492 0.240 34.17580 -118.3169 168 0.31
174 1988 2596 0.280 34.00056 -117.4153 250 0.31
175 1988 2499 0.290 34.24139 -117.2756 1384 0.31
176 1988 2589 0.220 32.63140 -117.0592 56 0.31
177 1988 2420 0.250 34.19917 -118.5328 226 0.31
178 1988 2898 0.290 34.06667 -117.7500 270 0.31
179 1988 2991 0.160 34.25220 -119.1431 34 0.31
180 1988 2899 0.210 34.06640 -118.2267 87 0.31
181 1989 2410 0.120 38.10250 -122.2381 30 0.33
182 1989 2199 0.190 33.81944 -116.4900 171 0.33
183 1989 2484 0.330 34.13640 -117.9239 183 0.33
184 1989 2125 0.100 37.48250 -122.2033 9 0.33
185 1989 2040 0.230 32.83640 -117.1289 135 0.33
186 1989 2525 0.210 33.78889 -117.2278 439 0.33
187 1989 2293 0.120 37.53583 -121.9617 24 0.33
188 1989 2008 0.190 34.46222 -120.0258 24 0.33
189 1989 2589 0.160 32.63140 -117.0592 56 0.33
190 1989 2420 0.230 34.19917 -118.5328 226 0.33
191 1989 2460 0.200 32.84220 -116.7683 603 0.33
192 1989 2102 0.110 38.01694 -121.8836 9 0.33
193 1989 2898 0.250 34.06667 -117.7500 270 0.33
194 1989 2991 0.190 34.25220 -119.1431 34 0.33
195 1989 2655 0.100 38.31139 -122.2942 22 0.33
196 1989 2249 0.260 33.92528 -117.9522 82 0.33
197 1989 2596 0.270 34.00056 -117.4153 250 0.33
198 1989 2492 0.200 34.17580 -118.3169 168 0.33
199 1989 2899 0.250 34.06640 -118.2267 87 0.33
200 1989 2499 0.270 34.24139 -117.2756 1384 0.33
201 1990 2199 0.170 33.81944 -116.4900 171 0.33
202 1990 2008 0.110 34.46222 -120.0258 24 0.33
203 1990 2410 0.110 38.10250 -122.2381 30 0.33
205 1990 2484 0.230 34.13640 -117.9239 183 0.33
206 1990 2293 0.130 37.53583 -121.9617 24 0.33
207 1990 2040 0.200 32.83640 -117.1289 135 0.33
208 1990 2589 0.150 32.63140 -117.0592 56 0.33
209 1990 2525 0.190 33.78889 -117.2278 439 0.33
210 1990 2460 0.170 32.84220 -116.7683 603 0.33
211 1990 2102 0.110 38.01694 -121.8836 9 0.33
212 1990 2596 0.290 34.00056 -117.4153 250 0.33
213 1990 2420 0.190 34.19917 -118.5328 226 0.33
215 1990 2249 0.210 33.92528 -117.9522 82 0.33
216 1990 2899 0.200 34.06640 -118.2267 87 0.33
217 1990 2898 0.240 34.06667 -117.7500 270 0.33
218 1990 2492 0.200 34.17580 -118.3169 168 0.33
219 1990 2499 0.330 34.24139 -117.2756 1384 0.33
220 1990 2991 0.120 34.25220 -119.1431 34 0.33
221 1991 2008 0.110 34.46222 -120.0258 24 0.33
222 1991 2199 0.180 33.81944 -116.4900 171 0.33
224 1991 2040 0.180 32.83640 -117.1289 135 0.33
226 1991 2293 0.120 37.53583 -121.9617 24 0.33
227 1991 2249 0.210 33.92528 -117.9522 82 0.33
228 1991 2484 0.280 34.13640 -117.9239 183 0.33
229 1991 2525 0.200 33.78889 -117.2278 439 0.33
230 1991 2460 0.150 32.84220 -116.7683 603 0.33
231 1991 2410 0.110 38.10250 -122.2381 30 0.33
232 1991 2420 0.220 34.19917 -118.5328 226 0.33
233 1991 2655 0.110 38.31139 -122.2942 22 0.33
234 1991 2499 0.270 34.24139 -117.2756 1384 0.33
235 1991 2492 0.220 34.17580 -118.3169 168 0.33
236 1991 2898 0.240 34.06667 -117.7500 270 0.33
237 1991 2991 0.120 34.25220 -119.1431 34 0.33
238 1991 2596 0.240 34.00056 -117.4153 250 0.33
239 1991 2589 0.150 32.63140 -117.0592 56 0.33
240 1991 2899 0.190 34.06640 -118.2267 87 0.33
242 1992 2991 0.141 34.25220 -119.1431 34 0.33
243 1992 2898 0.260 34.06667 -117.7500 270 0.33
244 1992 2420 0.170 34.19917 -118.5328 226 0.33
245 1992 2040 0.160 32.83640 -117.1289 135 0.33
246 1992 2899 0.200 34.06640 -118.2267 87 0.33
247 1992 2596 0.260 34.00056 -117.4153 250 0.33
248 1992 2484 0.270 34.13640 -117.9239 183 0.33
249 1992 2199 0.150 33.81944 -116.4900 171 0.33
250 1992 2008 0.130 34.46222 -120.0258 24 0.33
251 1992 2589 0.150 32.63140 -117.0592 56 0.33
252 1992 2460 0.170 32.84220 -116.7683 603 0.33
253 1992 2410 0.100 38.10250 -122.2381 30 0.33
255 1992 2525 0.210 33.78889 -117.2278 439 0.33
256 1992 2499 0.280 34.24139 -117.2756 1384 0.33
257 1992 2293 0.120 37.53583 -121.9617 24 0.33
258 1992 2249 0.210 33.92528 -117.9522 82 0.33
259 1992 2102 0.110 38.01694 -121.8836 9 0.33
260 1992 2492 0.220 34.17580 -118.3169 168 0.33
261 1993 2525 0.200 33.78889 -117.2278 439 0.33
262 1993 2499 0.240 34.24139 -117.2756 1384 0.33
263 1993 2492 0.180 34.17580 -118.3169 168 0.33
264 1993 2199 0.170 33.81944 -116.4900 171 0.33
265 1993 2460 0.187 32.84220 -116.7683 603 0.33
266 1993 2899 0.160 34.06640 -118.2267 87 0.33
267 1993 2125 0.100 37.48250 -122.2033 9 0.33
268 1993 2102 0.130 38.01694 -121.8836 9 0.33
269 1993 2008 0.110 34.46222 -120.0258 24 0.33
270 1993 2249 0.190 33.92528 -117.9522 82 0.33
271 1993 2589 0.133 32.63140 -117.0592 56 0.33
272 1993 2991 0.138 34.25220 -119.1431 34 0.33
273 1993 2898 0.210 34.06667 -117.7500 270 0.33
274 1993 2655 0.120 38.31139 -122.2942 22 0.33
275 1993 2040 0.146 32.83640 -117.1289 135 0.33
276 1993 2484 0.240 34.13640 -117.9239 183 0.33
277 1993 2596 0.260 34.00056 -117.4153 250 0.33
278 1993 2420 0.190 34.19917 -118.5328 226 0.33
279 1993 2410 0.110 38.10250 -122.2381 30 0.33
280 1993 2293 0.130 37.53583 -121.9617 24 0.33
281 1994 2420 0.140 34.19917 -118.5328 226 0.34
282 1994 2898 0.241 34.06667 -117.7500 270 0.34
284 1994 2525 0.184 33.78889 -117.2278 439 0.34
285 1994 2410 0.100 38.10250 -122.2381 30 0.34
286 1994 2293 0.120 37.53583 -121.9617 24 0.34
288 1994 2499 0.265 34.24139 -117.2756 1384 0.34
289 1994 2484 0.251 34.13640 -117.9239 183 0.34
290 1994 2249 0.252 33.92528 -117.9522 82 0.34
291 1994 2991 0.115 34.25220 -119.1431 34 0.34
292 1994 2596 0.253 34.00056 -117.4153 250 0.34
293 1994 2460 0.147 32.84220 -116.7683 603 0.34
294 1994 2199 0.165 33.81944 -116.4900 171 0.34
295 1994 2040 0.102 32.83640 -117.1289 135 0.34
296 1994 2899 0.193 34.06640 -118.2267 87 0.34
297 1994 2492 0.167 34.17580 -118.3169 168 0.34
298 1994 2102 0.111 38.01694 -121.8836 9 0.34
299 1994 2008 0.106 34.46222 -120.0258 24 0.34
301 1995 2040 0.120 32.83640 -117.1289 135 0.37
302 1995 2249 0.160 33.92528 -117.9522 82 0.37
303 1995 2199 0.160 33.81944 -116.4900 171 0.37
304 1995 2008 0.135 34.46222 -120.0258 24 0.37
305 1995 2102 0.124 38.01694 -121.8836 9 0.37
306 1995 2420 0.145 34.19917 -118.5328 226 0.37
307 1995 2410 0.133 38.10250 -122.2381 30 0.37
308 1995 2125 0.140 37.48250 -122.2033 9 0.37
309 1995 2492 0.165 34.17580 -118.3169 168 0.37
310 1995 2499 0.256 34.24139 -117.2756 1384 0.37
311 1995 2484 0.212 34.13640 -117.9239 183 0.37
312 1995 2293 0.153 37.53583 -121.9617 24 0.37
313 1995 2460 0.146 32.84220 -116.7683 603 0.37
314 1995 2589 0.140 32.63140 -117.0592 56 0.37
315 1995 2525 0.202 33.78889 -117.2278 439 0.37
316 1995 2655 0.130 38.31139 -122.2942 22 0.37
317 1995 2899 0.167 34.06640 -118.2267 87 0.37
318 1995 2898 0.215 34.06667 -117.7500 270 0.37
319 1995 2596 0.213 34.00056 -117.4153 250 0.37
320 1995 2991 0.124 34.25220 -119.1431 34 0.37
321 1996 2008 0.120 34.46222 -120.0258 24 0.40
322 1996 2410 0.112 38.10250 -122.2381 30 0.40
323 1996 2420 0.205 34.19917 -118.5328 226 0.40
324 1996 2102 0.121 38.01694 -121.8836 9 0.40
325 1996 2040 0.120 32.83640 -117.1289 135 0.40
327 1996 2125 0.097 37.48250 -122.2033 9 0.40
328 1996 2492 0.142 34.17580 -118.3169 168 0.40
329 1996 2199 0.160 33.81944 -116.4900 171 0.40
330 1996 2898 0.187 34.06667 -117.7500 270 0.40
331 1996 2484 0.196 34.13640 -117.9239 183 0.40
332 1996 2293 0.100 37.53583 -121.9617 24 0.40
333 1996 2249 0.150 33.92528 -117.9522 82 0.40
334 1996 2899 0.144 34.06640 -118.2267 87 0.40
335 1996 2525 0.180 33.78889 -117.2278 439 0.40
336 1996 2460 0.138 32.84220 -116.7683 603 0.40
338 1996 2499 0.234 34.24139 -117.2756 1384 0.40
339 1996 2991 0.121 34.25220 -119.1431 34 0.40
340 1996 2596 0.203 34.00056 -117.4153 250 0.40
341 1997 2410 0.103 38.10250 -122.2381 30 0.42
342 1997 2040 0.115 32.83640 -117.1289 135 0.42
343 1997 2420 0.121 34.19917 -118.5328 226 0.42
344 1997 2199 0.155 33.81944 -116.4900 171 0.42
345 1997 2589 0.117 32.63140 -117.0592 56 0.42
349 1997 2898 0.156 34.06667 -117.7500 270 0.42
350 1997 2484 0.162 34.13640 -117.9239 183 0.42
351 1997 2492 0.134 34.17580 -118.3169 168 0.42
352 1997 2249 0.134 33.92528 -117.9522 82 0.42
353 1997 2991 0.102 34.25220 -119.1431 34 0.42
354 1997 2525 0.136 33.78889 -117.2278 439 0.42
355 1997 2293 0.109 37.53583 -121.9617 24 0.42
356 1997 2899 0.120 34.06640 -118.2267 87 0.42
358 1997 2460 0.136 32.84220 -116.7683 603 0.42
359 1997 2596 0.187 34.00056 -117.4153 250 0.42
360 1997 2499 0.205 34.24139 -117.2756 1384 0.42
361 1998 2040 0.125 32.83640 -117.1289 135 0.44
363 1998 2102 0.097 38.01694 -121.8836 9 0.44
364 1998 2492 0.177 34.17580 -118.3169 168 0.44
365 1998 2249 0.182 33.92528 -117.9522 82 0.44
366 1998 2410 0.119 38.10250 -122.2381 30 0.44
367 1998 2199 0.173 33.81944 -116.4900 171 0.44
368 1998 2420 0.161 34.19917 -118.5328 226 0.44
369 1998 2484 0.195 34.13640 -117.9239 183 0.44
370 1998 2293 0.115 37.53583 -121.9617 24 0.44
373 1998 2525 0.149 33.78889 -117.2278 439 0.44
374 1998 2460 0.164 32.84220 -116.7683 603 0.44
375 1998 2899 0.148 34.06640 -118.2267 87 0.44
376 1998 2898 0.184 34.06667 -117.7500 270 0.44
377 1998 2655 0.125 38.31139 -122.2942 22 0.44
378 1998 2499 0.244 34.24139 -117.2756 1384 0.44
379 1998 2991 0.106 34.25220 -119.1431 34 0.44
380 1998 2596 0.195 34.00056 -117.4153 250 0.44
382 1999 2040 0.104 32.83640 -117.1289 135 0.47
383 1999 2410 0.113 38.10250 -122.2381 30 0.47
385 1999 2199 0.126 33.81944 -116.4900 171 0.47
386 1999 2008 0.088 34.46222 -120.0258 24 0.47
387 1999 2293 0.133 37.53583 -121.9617 24 0.47
388 1999 2525 0.112 33.78889 -117.2278 439 0.47
389 1999 2492 0.120 34.17580 -118.3169 168 0.47
390 1999 2249 0.116 33.92528 -117.9522 82 0.47
391 1999 2589 0.105 32.63140 -117.0592 56 0.47
392 1999 2655 0.115 38.31139 -122.2942 22 0.47
393 1999 2420 0.100 34.19917 -118.5328 226 0.47
394 1999 2484 0.137 34.13640 -117.9239 183 0.47
395 1999 2898 0.141 34.06667 -117.7500 270 0.47
396 1999 2596 0.142 34.00056 -117.4153 250 0.47
397 1999 2460 0.124 32.84220 -116.7683 603 0.47
398 1999 2899 0.128 34.06640 -118.2267 87 0.47
399 1999 2991 0.103 34.25220 -119.1431 34 0.47
400 1999 2499 0.174 34.24139 -117.2756 1384 0.47
402 2000 2125 0.083 37.48250 -122.2033 9 0.50
403 2000 2199 0.124 33.81944 -116.4900 171 0.50
404 2000 2249 0.137 33.92528 -117.9522 82 0.50
405 2000 2040 0.118 32.83640 -117.1289 135 0.50
406 2000 2420 0.109 34.19917 -118.5328 226 0.50
407 2000 2492 0.152 34.17580 -118.3169 168 0.50
408 2000 2293 0.102 37.53583 -121.9617 24 0.50
409 2000 2102 0.107 38.01694 -121.8836 9 0.50
410 2000 2460 0.121 32.84220 -116.7683 603 0.50
411 2000 2484 0.174 34.13640 -117.9239 183 0.50
413 2000 2410 0.079 38.10250 -122.2381 30 0.50
414 2000 2898 0.152 34.06667 -117.7500 270 0.50
416 2000 2499 0.176 34.24139 -117.2756 1384 0.50
417 2000 2525 0.164 33.78889 -117.2278 439 0.50
419 2000 2596 0.140 34.00056 -117.4153 250 0.50
420 2000 2899 0.136 34.06640 -118.2267 87 0.50
421 2001 2040 0.135 32.83640 -117.1289 135 0.52
422 2001 2199 0.137 33.81944 -116.4900 171 0.52
424 2001 2102 0.118 38.01694 -121.8836 9 0.52
425 2001 2492 0.129 34.17580 -118.3169 168 0.52
426 2001 2249 0.114 33.92528 -117.9522 82 0.52
428 2001 2125 0.105 37.48250 -122.2033 9 0.52
429 2001 2484 0.189 34.13640 -117.9239 183 0.52
430 2001 2293 0.109 37.53583 -121.9617 24 0.52
431 2001 2460 0.135 32.84220 -116.7683 603 0.52
432 2001 2420 0.140 34.19917 -118.5328 226 0.52
433 2001 2589 0.102 32.63140 -117.0592 56 0.52
434 2001 2525 0.152 33.78889 -117.2278 439 0.52
435 2001 2898 0.144 34.06667 -117.7500 270 0.52
437 2001 2499 0.170 34.24139 -117.2756 1384 0.52
438 2001 2596 0.143 34.00056 -117.4153 250 0.52
439 2001 2899 0.116 34.06640 -118.2267 87 0.52
441 2002 2040 0.112 32.83640 -117.1289 135 0.55
443 2002 2102 0.111 38.01694 -121.8836 9 0.55
444 2002 2492 0.128 34.17580 -118.3169 168 0.55
445 2002 2199 0.136 33.81944 -116.4900 171 0.55
446 2002 2410 0.109 38.10250 -122.2381 30 0.55
448 2002 2293 0.110 37.53583 -121.9617 24 0.55
449 2002 2249 0.121 33.92528 -117.9522 82 0.55
450 2002 2420 0.152 34.19917 -118.5328 226 0.55
451 2002 2484 0.136 34.13640 -117.9239 183 0.55
452 2002 2525 0.147 33.78889 -117.2278 439 0.55
453 2002 2460 0.121 32.84220 -116.7683 603 0.55
454 2002 2499 0.161 34.24139 -117.2756 1384 0.55
455 2002 2589 0.115 32.63140 -117.0592 56 0.55
456 2002 2898 0.150 34.06667 -117.7500 270 0.55
457 2002 2655 0.116 38.31139 -122.2942 22 0.55
459 2002 2596 0.155 34.00056 -117.4153 250 0.55
460 2002 2899 0.122 34.06640 -118.2267 87 0.55
461 2003 2199 0.141 33.81944 -116.4900 171 0.58
463 2003 2040 0.107 32.83640 -117.1289 135 0.58
464 2003 2249 0.165 33.92528 -117.9522 82 0.58
465 2003 2410 0.101 38.10250 -122.2381 30 0.58
467 2003 2492 0.134 34.17580 -118.3169 168 0.58
468 2003 2499 0.163 34.24139 -117.2756 1384 0.58
469 2003 2420 0.179 34.19917 -118.5328 226 0.58
470 2003 2125 0.113 37.48250 -122.2033 9 0.58
471 2003 2293 0.123 37.53583 -121.9617 24 0.58
472 2003 2596 0.169 34.00056 -117.4153 250 0.58
474 2003 2484 0.150 34.13640 -117.9239 183 0.58
475 2003 2460 0.125 32.84220 -116.7683 603 0.58
476 2003 2899 0.152 34.06640 -118.2267 87 0.58
477 2003 2525 0.155 33.78889 -117.2278 439 0.58
478 2003 2655 0.105 38.31139 -122.2942 22 0.58
479 2003 2898 0.161 34.06667 -117.7500 270 0.58
482 2004 2040 0.105 32.83640 -117.1289 135 0.61
483 2004 2125 0.097 37.48250 -122.2033 9 0.61
484 2004 2008 0.109 34.46222 -120.0258 24 0.61
485 2004 2484 0.134 34.13640 -117.9239 183 0.61
486 2004 2492 0.137 34.17580 -118.3169 168 0.61
487 2004 2199 0.125 33.81944 -116.4900 171 0.61
488 2004 2410 0.104 38.10250 -122.2381 30 0.61
489 2004 2525 0.128 33.78889 -117.2278 439 0.61
492 2004 2420 0.131 34.19917 -118.5328 226 0.61
494 2004 2460 0.106 32.84220 -116.7683 603 0.61
495 2004 2589 0.097 32.63140 -117.0592 56 0.61
497 2004 2499 0.163 34.24139 -117.2756 1384 0.61
498 2004 2898 0.131 34.06667 -117.7500 270 0.61
499 2004 2899 0.110 34.06640 -118.2267 87 0.61
500 2004 2596 0.141 34.00056 -117.4153 250 0.61
503 2005 2420 0.138 34.19917 -118.5328 226 0.62
506 2005 2199 0.139 33.81944 -116.4900 171 0.62
507 2005 2899 0.121 34.06640 -118.2267 87 0.62
511 2005 2898 0.140 34.06667 -117.7500 270 0.62
513 2005 2484 0.145 34.13640 -117.9239 183 0.62
514 2005 2492 0.142 34.17580 -118.3169 168 0.62
516 2005 2525 0.126 33.78889 -117.2278 439 0.62
517 2005 2460 0.113 32.84220 -116.7683 603 0.62
518 2005 2293 0.105 37.53583 -121.9617 24 0.62
519 2005 2596 0.144 34.00056 -117.4153 250 0.62
520 2005 2499 0.182 34.24139 -117.2756 1384 0.62
521 2006 2499 0.164 34.24139 -117.2756 1384 0.62
522 2006 2898 0.151 34.06667 -117.7500 270 0.62
523 2006 2525 0.169 33.78889 -117.2278 439 0.62
525 2006 2596 0.151 34.00056 -117.4153 250 0.62
526 2006 2420 0.158 34.19917 -118.5328 226 0.62
527 2006 2199 0.126 33.81944 -116.4900 171 0.62
528 2006 2460 0.121 32.84220 -116.7683 603 0.62
529 2006 2899 0.108 34.06640 -118.2267 87 0.62
530 2006 2492 0.166 34.17580 -118.3169 168 0.62
533 2006 2249 0.146 33.92528 -117.9522 82 0.62
535 2006 2293 0.102 37.53583 -121.9617 24 0.62
537 2006 2102 0.105 38.01694 -121.8836 9 0.62
538 2006 2040 0.108 32.83640 -117.1289 135 0.62
539 2006 2484 0.165 34.13640 -117.9239 183 0.62

7 Ozone concentration Vs. Global Temperature over time

The animated plot below shows how the ozone concentration and global temperature has changed over time. This shows that on average the overall ozone concentration and range has decreased even though the global temperature has steadily increased. This could be due to many different variables but most likely is from stricter emissions regulations in California. Since ozone is formed from the reaction between UV and other air pollutants, reducing the concentration of air pollutants would reduce the ozone concentration even if UV intensity increased.

8 Ozone Concentration Over Time

We saw previously that the annual average ozone concentration was decreasing and the range was narrowing. To see how the concentration at all locations has changed over time, the scatter plot below was created. This shows a steeps decrease in ozone concentration from the year 1980 to 2000, with a plateau from 2000 to 2005.

9 Correlation of parameters

Looking at the correlation plot, we see that a few parameters are highly correlated (positive and negative), however many do not seem to be correlated at all. Of note, ozone appears to be negatively correlated with No, NOx and, NO2 which is to be expected since NOx will react in the atmosphere to produce ozone. Since there are some correlation between these contaminants, a simple linear regression model was trained to predict ozone concentrations given the other pollutant concentrations.

10 Building a Linear Model

The linear regression model was trained using a 80:20 split for training and testing data at random time points throughout the main dataframe. The correlation between the actual ozone concentration and the predicted values was found to be 0.75. This correlation is not entirely bad, but other machine learning models may be able to get a better fit. By comparing the actual vs. predicted values over time, we see that the linear model follows the general trend of the concentrations, but does over fit occasionally.

11 XGBoost predictive model

XGBoost is a variation of the Gradient Boosted Decision Trees algorithm. Essentially, this work by going through cycles that repeatedly build new models and combine them into a group of models. The cycle begins by calculating the errors in an existing model for each observation in the data set. A new model is then built to predict these errors. The predictions are then moved from this error-predicting model to the group of models. This cycle continues for the number of iterations specified.

The model was built using a logistic regression objective function, with 32. The number of iterations was optimized by running cross validation on the dataset for 100 iterations and finding the stabilization point. Since this is time series data, the time data was split into month and year columns to account for seasonal variability. The correlation between the actual ozone concentration and the predicted was found to be 0.89. This value is much higher than the basic linear model and could be further optimized by varying other model parameters such as early stopping rounds, objective function, and max depth. When plotting the actual and predicted concentrations over time, we can see that the XGBoost model follows the actual trend much more closely than the linear model, but could still be tuned for proper fitting.